Adjustable drill head



i/ 1948- H. o. SCHULTZ ADJUSTABLE DRILL HEAD Filed Nov. 29, 1944 2 Sheets-Sheet l INVENTOR.

ATTo A/EKs.

y 18, 1943' H. o. SCHULTZ 2,441,722

ADJUSTABLE DRILL HEAD Filed NOV. 29, 1944 2 Sheets-Sheet 2 A TTORA/E V5.

Patented May 18, 1948 ADJUSTABLE DRILL HEAD Henry 0. Schultz, Milwaukee, Wis., assignor to R0. Schultz, Inc;, Milwaukee, Wis., a corporation of Wisconsin Application.Noveinber 29, 1944, Serial No. 565,628

This invention relates in' general to improvements in the art of drilling and .relates more specifically to improvements -in the construction and operation of mechanism 'for' simultaneously driving two or more drills while they. are located in pre-selected positions of adjustment.

The principal object of my invention is to'pro vldei'an improved adjustable drill head or multi-' ple'drill drive, which is simple and compact in: construction}, flexible in its adaptations, and

, mit the formation ofholes arranged in diverse patterns, these prior devices have not been entirely satisfactory for various-reasons While some of the previous drill driving heads were capable of adjustment so as] to vary the radii of bolt circles on which the groups of holes could be simultaneously drilled, the'drillingswere lim ited to circular patterns and could, not be readily applied to straight line, rectangular, and other diversejand irregular arrangements, thus materially restricting the utility of these appliances; In most of the prior multiple drill drives, the, drill driving spindles while being adapted forfrelatively rapid adjustment, were not properly sup ported against undesirable displacement after the adjustments were effected, and they were also considerably limited as to range offadjust ment'of the drills. Then too,'the driving gears or other motion transmitting elements of tmany of these prior devices, were not properly lubricated and were subjected to'unnecessary pressures and forces which resulted in undesirably high power consumption; and most of the previrelatively cumbersome, complicated, and costly to produce and to maintain. Forthese and many other specific reasons, the previously proposed multiple drill heads have not proven popular with the trade, except perhaps for special pur poses suchas the production of groups of holes arranged in circles of difierentselected diameters.

It is thereforea more specific object of the present invention to provide an improved multiple drill driving assemblage wherein two or more drill driving spindles" are quickly and conveniently universally adjustable throughout an extensive area, and in which the drills are most effectively retained against undesirable dis- 1': Claims.

subsequent posltiveretention of the placement after each adjustment or change in location thereof has been effected. j I "Another'specific object of this invention is to provide an improved driving mechanismior si-" multaneously rotating a multiplicity of twist drills, andfol effectively selective positioning the drill axes in a variety of definite patterns in; volving either straight or curved row arrange-' ment of these" axes and diverse spacing thereof; A further specific object of my invention is ,to provide an improved compact andpowerfulidrlll driving head for simultaneously propelling a considerable number of individual drills or the like, and for permitting preselected location of the several drills in circles, polygons, or other patterns throughout an area of considerably eater magnitude than the cross-sectional area of'the head.

An additional specific object of the invention is to provide animproved multiple drill head wherein' the end thrust on theindividual drills is most efiectively absorbed without subjecting .the motion transmitting gears or other drivingelements to undesirable pressure, and in which all moving parts are abundantly lubricated at all e -v I 7 Still another specific object of this invention isto provide improved instrumentalities for effecting rapid and accurate selective positioning of a" multiplicity'of individual drill spindles, and spindles in thedesired locations.

Another specific object of my invention is to provide a durable multi-drill assembly which may be manufactured and maintained at moderate cost while being extremely flexible in its uses, and wherein drills of various sizes may be readily applied and removedand are 'most effectively driven while in use; j

- tagesof the invention will be apparent from ous multiple drill driving assemblages were also T heseand other specific objects and advanthe following detaileddescriptioni U f Aclear conception of the several features constituting my invention, and of themode of constructing and of utilizing multiple drill heads embodying the im rovement, may be had by referring to the drawings accompanying and for ming apart-of this'specification wherein like reference characters designate the'same or similar parts and to also assist in holding the spindies in:de+-' sired position;

Fig. 5 is a similarly reducedipla'n View of the.

lower positioning and spindle retaining template which is finally associated with the multiple drill head to hold the spindles as in Fig-35 Fig. 6 is a somewhat enlarged central=vertioalisection through one of my improved drill adaptors which constitute part ofthe rotary drill spindles;

Figi 7 is a similarly enlarged side elevation of one of the improved drlllh'o'lding collets' which are normallycarrie'd by the improvedadaptors;

Fig. 8 is a fragmentary section through". the multiple drill head taken radially through the oil level indicator of the lubricant supply reservoir.

Fig; 9 is a fragmentary bottom view of one or: the six doub1e-eccentric drill spindle adjust ihg and driving assemblages; and

Fig. 10 is a fragmentary-section throughthe spindle adjusting, holding and driving assemblage of Fig. 9.

While the invention has been shown and described herein asbeing embodied in a typical six spindle gear driven multiple drill head having special holding templates and drill adaptors associated therewith, it is not my desire or intentic-h to thereby unnecessarily restrict thescope or limit the utility of the improvements which are obviously more generally. applicable.

Referringto the drawings, theimproved multiple d'rill head shown therein comprises in generalian annular upperbody orv gear casing [2 having a top closure or cover plate l3 coacting therewith to form an annular lubricant chamber M; a main-driving gear l'5ljournalled centrally withinth'e casing- 12' and plate. l3 for rotation Within the chamber M; an adaptor orrigid sup. port I6 for fixedl suspending. the. plate l3. and casing l2 from stationary parts of a drill. press or the like; a main drive shaft H detachably connected to the main gear l5 within the adaptor support I6; six equally spaced. countershafts l8 also journalledin the cover plate [3 andin bear.- ing bushings [9 carried by the. casing I2, and each having an upper gear 21! andla lower. gear 2i drivingly attached thereto; six idler gears22driv- 4 ings being swingably adjustable about the fixed axes of the adjacent countershafts l8; a series of six drill spindle shafts each having a driving gear 3| coacting with the adjacent lower idler gear 28 and also having a lower drill adaptor socket 32 at its lower end; a spindle housing 33 rotatably. supporting each shait.30 and. enclosing theadjacent gear'3l, thesehousings being swingably suspended from the adjacent idler housings 29 for adjustment about the adjustable axes of the corresponding idler shafts 26; a clamping nut 3 coacting with end screw threads formed on eachidlershaft 25 and with the adjacent spindle housing.33'lto fir-mly lock the relatively eccentric tel'e'seopicallymounted housings 29, 33 in various positions of adjustment; a pair of upper and lower mutually coacting spindle retaining templates--35, 36 respectively, suspended from the main casing l2 by means of rigid columns 31 and cap screws 38, andbeing formed to engage the spindle housings 33 through bushings". 3'9 carriedby-thesehousin'gs;"and an improved adaptor 40""f01 effecting detachable connectionv of the. drills toeach of the sockets 32'.

Thecoverpl'ate' l3" may be properly positioned and firmly secured to the annular main casing l2 with the aid of dowels: 417 and headless screws 42;andthe suspensionsupport 16 may likewise be detachably secured'to" the top plate 13 by ingly connecting the main gear l5 withthe adjace'nt upper gears 20} withinthe. chamber 14;. an annular series of six rotary adjusting andclamping rings 23 confined within equally spaced ann'ular lower recesses 24 formed in the-casing l2 and'each having peripheral coaction witha-lower l plate 2 5 -Which is rigidly secured to the casing l2; each of the rings 23. having an idler shaft 26" formed integral. therewith and depending therefrom;v an idler gear assemblage consisting of integrally united upper and lower gears21', 28:.respectively, rotatable about each idler shaft 26,.1 and having their uppergears 2! in driving coaction-with the). adjacent lower: drivegears 2 l.; anidler housing 29 enclosingceach setof coacting gears 2|, 2T andengaging the bottomsofthe adjacent rings 23 and lower plate 25,"these housmeans of headless screws"43,as shown in Fig; 2, in order to avoid externalprojections while still permitting ready assembly and dismantling of these parts The lubricant chamber I4. of. the main casing IZ'may'a'lso be'provided with" a suitable filling opening and with an oil level. indie cator 44" asv shown in Figs. 1'and8, in order. to provide a sight indication'iof the oil'level'within thischamber." Oil from within this. lubricant chamber [4,besides maintaining the gears 15; 20'; 22 properly lubricated at'all times, is adapted to flow by gravity along. the bearing bushings l91and shafts IBaintoLtheidIer housing 29, and from thence-pastthe gearsZl, 21 into the spindle housing 33. While'thus' flowing past the several gears and. alongthe shafts confined within the housings 29, 33; .the oil will obviously maintain all moving parts well lubricated at all times,.and fresh" lubricant maybe periodically admitted-to the'supply chamber l4;

The housings 29; 33 may be eifectively sealed against undesirably free escape of lubricant, in any uitable manner; and the. double eccentricity or adjustment afforded by thesepivotally interconnected housings 291.33 and the locking or clamping afforded by'the rings 23; shafts ZB and nuts 34',--con'stitute important featuresof the pres.- ent invention- As clearly illustrated in Figs. 1', 3, "9 andrlO, each of the drill carrying spindle shafts 30; is adjustable, about the correspondin'g driving countershait l8; independently of all others, and the. axesof the severaldrill carrying shafts 30 may be disposed anywhere within the limits of swing of" the combined radiiof swing of the two housings 29, 3 3 constituting each set, about it'sfixed pivot shafit l 8 As shown in -Fig.'1-, the two housings 29533 have been-adjusted to themaximum extent: sothat the shaft: 30 is: in the extreme position: :away"from the: corres=ponding..pivbb' shaft l8; The. drill carryingxshaftstil may: however be swung; into axial-aliriem'ent with the-correspondingcountershaft 18;: or it maybe shifted. about the-adj acent idlershaft 2Bto any other intervening position :with respect. to the fixed counter .shaft I8; thus providing-extreme flexibility in the assemblage.

The various adjustments ofthe individual spindle sh'afts 39- may be quickly and conveniently made upon removal of the templates'35, 36 and release of the clamping nuts 34, and these templates may be formed of sheet metal and of diverse patterns corresponding to the work which is tobe performed. -As illustrated in Figs. 3, 4 and 5, the templates 35, 36 have been constructed-so as to position the drill spindle shafts 39 in rectangular formation, and when utilizing templates of a definite predetermined shape, the nuts 34 may be released suffioiently to permit relatively free swinging of the housings 29, 33 about their respective shafts I8, 23, whereupon the centrally open upper template 35 may be applied to the columns 31 with the bushings 39 projecting through the central opening.- The bushings 39 may then be swung and positioned within the side and corner notches 45, 46 of the central template opening, whereupon the initial positioning template 35 may be carefully removed and the nuts 34 should be tightened to clamp the housings 29, 33 in the desired position. The upper and lower templates 35, 39 may thereafter be applied in succession and firmly secured to the columns 31 with the aid of the set screws 33, whereupon the notches 45, 45 and the alined round holes 31 of the lower template'eli will maintain the spindle shafts 39 in proper desired position. 2

As previously indicated, the adjusting and clamping rings 23 aresnugly confined within circular recesses 24 formed in the main'casing l2, and coact with the flat bottom plate 25 which is firmly but detachably secured to the'bottom of the casing l2 by means of screws or otherwise. The idler shafts 25 are firmly attached to or formed integral with their respective'rings 23, so that these shafts may he swung about the axes of the adjacent countershafts l8, by revolving the corresponding rings 23 when the nuts 34 have been released. However, when the clamping nuts 34 are tightened, these nuts clampthe telescopic spindle housings 33 against the adjacent idler housings 29, and also firmly clamp the housings 29 against the lower plate 25, by pulling the peripheral edges of therings 23 snugly against this plate 25, so that the housings 29, 33 cannot thereafter move out of their adjusted and clamped positions. This clamping is also effected so as to avoid-clamping the enclosed gears 2|, '21, '28, 3|, and in order to-avoid'having the end thrust introduced by the individual drills, shift the spindle shafts 30' upwardly into the housings 33, anti-friction or ball thrust bearings 48 are preferably introduced between the sockets 32 and bushings 39, as shown in Fig. 1.

In order to permit rapid and convenient interchanging of drills, and'in view of the fact that the spindle sockets 32 are formed integral with or are permanently rigidly united with their spindle shafts 39, special drill adaptors 49 are preferably provided. The detailed construction of these adaptors is shown in Figs. 6 and '7, and each adaptor 49 comprises an elongated cylindrical member 59 snugly fitted within the bore of the spindle socket 32 and having a key 5! secured to one side thereof which is slidably 'cooperable with a key-way 52 formed in the socket, while its opposite side is provided with a tapered groove 53 adapted to coact with a retaining screw 54 carried by the socket 32; athrust collar 55 having screw thread coaction with the outer end of the member 50 and being provided with another set screw' 56 adapted to coact with a recess 51 formed in the member '50, so as to lock this memberin axially adjusted position: a split col-' let 58*having tapered jaws 59 cooperable with the shank of a twist drill and with the tapered bore 69 of the member 59, and also being provided with a polygonal upper and BI adapted to snugly fit a similarly polygonal pocket 62 formed in the'member 59; and-a drill clamping screw 63 oooperable with the member 50 and withthe collet 58 in order to draw the latter within the bore 69 so as to cause the jaws 59 to firmly clamp the drill shank. The collets 53 may be provided with drill shank engaging'bores of different diameters adapted to receive drillsof different sizes, but all having tapered jaws 59 which are snugly cooperable with the tapered bore 69 of the member, 59, and the upper ends of thejaws 59 are separated by a slot 64 which is formed to fit the upper flat ends of the drill shanks. The improved adaptors 4B are therefore capable of cooperating with standard twist drills of various sizes, and these drills may obviously be readily applied or removed and are firmly clamped within the collets 58 when properly applied thereto.

-During normal use of the improved multiple drill assemblage, the unit may be readily attached to or removed from the drill press with the aid of the adaptor support IS, in a manner well known to those skilled in the art, whenever necessary;

Templates of any. suitable configuration may then'be applied to the columns 31 and the spindle sockets 32 may be positioned to produce any desired pattern within the range of swinging adjustment afforded by the housings29, 33; and it is to be noted that the spindle sockets 32 may be located-considerably beyond the periphery of the main casing 12, if so desired. The individual twist drills may obviously be firmly clamped within the sockets 32 with the aid 'of the-ime proved adaptors 40, and the collets 58 will permit the" application of twist drills of different diameters, so that some of-these collets 58 may be provided with drills of a predetermined diam-.- eter whileothers may be providedi'with drills of larger or smaller diameters, thus enhancing the flexibility of the unit to a maximum. When the clamping nuts 34 have been placed into clamping position, and thetemplates 35, 36 as well as'the pro-selected drills have been properly applied, power may be applied to the main driving shaft and such application of power to the main driving shaft I! will thereafter be transmitted through the several trains of gears to the spindle shafts 30, and from thence to the individual drills so as topermit accurate drilling of holes following the pre-selected pattern formed, by the templates 35, 36. It is to be noted, however, that the use of these templates 35, 36 is not absolutely necessary since the clampingof the housings 29, 33 afiorded by the nuts 34, will rigidly hold the drill spindle shafts 30 in various positions of adjustment. The use of the templates 35, 36 is desirable'only when a large numberof successive groups of holes are to be drilled according to a predetermined pattern, and these templates 35, 36 will then afford additionalsupport for the housings 33 and spindlev shafts 30. The thrustinduced during drilling operations upon the spindle shafts 39 will be taken up by the anti-friction bearings 48 and'the gears 3|, 28, 21 will therefore be relieved of end thrust and will be freely rotatable with the application of minimum power. chamber I4 will gravitate alongthe shafts and past the several gears and will thus maintain all parts abundantly lubricated, so that the improved Oil from the 'is .universally; adjustahleithroughout an 1, extensive.-

area andiirnwhich the-.multiplicityof drills-zmaw bet positively-located. with; the drill spindles; adapted tm produce azvarietywof: patterns; The. improved -.:adjus.ting and: locking. assemblages: while: permitting; convenient: adjustment; of .tlie' drilli:spindles also:,-positiv.elyz lQCkSi theses spindles. in: various-spositions of: adjustment, and thee-spindle shaftsfimmayxbe; arranged:eithersinacunvedror; straight :lines 1 and; maybe brought; closely, adja,-.- cent .to eachrother: Any number zofi drillrspindles: may-obviously beeusedin. constructing? the H11? proyedaheads; and: by: utilizing equalj adjusting radii for; the eccentric housings. 29; -33;-1 the axes ofz-the spindle shafts- 3 -;may. be .broughtinto per fect .alinement .withzt'he axes ofithezfixedzcountershafts I8. The improvedftemplatesraserve to bothdefinitely locate the drills and to reinforce the spindles-mean the: work; and: also facilitate" quick: and:accurate:v adjustment of: the. drills.- so. as to followrdefinite patterns, and the, adjustingzrings. 23.:witn; their integral shafts .2 6: permit: clampingt'OrbE effe'eted asclose as possible totheax'esof the -spindle shafts Ms-and: of. theucountershaftsi 1812. The clampingeffect afforded by=the.nutsr3:4a producesrmetaleto metal clamping between. the; housing 33 andzthehousing 29, andalsobetmeen: thehousinglflrand .the fixed plat'e.=.-25;;.and the improved: adaptors t 4m besides permitting -quick: changingrofzdrills, also;insure.-rigidity.imthe assemblage andrprovideipositivedrives between the spindle. shafts and; the drills.. Theimproved' multiple-i drilkheads hasproven highly successful and flexible inzactual operation zand;mayiobviously. bes-Jmanufacturedr and-2: maintained in operating condition. at. moderate. cost.

It should. be understood that it 1 is; not desired to: limit: .thiseinventionxto the exact details of construction, or; to .the precise mode er; use,v herein. shownuand; described; for various mudifications; within the scope of the: appendedpclaimsmay oceun to persons. skilled in the art;

- l'claimz.

l. multiple; drill assemblagm. comprising, a. casing, a plurality; of counters-haits iournalled; in saidacasing, i means; for rotating. said. shafts; a clampingtring .adjustably revoluable: about: each oft.saidfcountershafts; each .of: .said.'.rings having an idlerwshaftsrigidly attached: thereto-tandex:- tend-ing. parallel to thev adjacent: countershaft; meanscoacting: with each. idler shaft i for: 01 amp..- ing the: adjacent ring to. said:.-casing,.a; spindle shaftigrevolvably adjustable; about; each; of; said idler: shafts; and gearing. drivingly interconnecting -the counter and: spindle ishafts. ofeachsset through-theintervening idler: shaft:

2 A :multiple: drill}; assemblage,a comprising; a casingda plurality of counters-baits journallecliin said :.-.casing, means for: rotatingwsaids; shafts; a clamping- -ringaadjustably. .revolvable'. about; each 0t said countershafts, each: of;v saidarings having an idlereshaft rigidly: attached theretoand ex: tending parallel 130113116 adjacent. countershaft; a spindle =shaitr; revolvably; adjustable aboutfeach of said idler. shafts,-gearing;drivingly; interconnect: ing:thescounteryandzspindle-shafts of each set thrcughithe.interueningiidlersshait;1 and common means.-. cooperating with) each; ois. saith rings III throngli:;zitslaidlen shaitcto;loclc the: spindle and idlen shafts;; of; each; sett in; various positions 1 of;

adjustments;

3.-'; Armultipleedrilli assemblage,- comprising; a;

eccentrically disposed.- idler shaft projecting;

therefrom; P?i .a1lelr'l70 ;the' ring, axis, an -id1er housin adjustalole about; each; of said; ring. axes and) coasting; with said casing; a-g spindle: hous--,-

ingreyolvably;adjustable about eachof-saididler shafts; and coacting with the-adjacent idler housin l. aespindleg. shaft-i journalled -in each: of

adjustable, upon, said; casing and each having an eccentrically; disposed-idler. shaft projecting therefrom parallel to. the; ring; axis,v an: idler. housing. adjustable-; about eachof-said ring axesandcOactingWith-Said casing; aspindle housing. revolvably; adjustable== about, eachyof said idler shafts .and; coacting -with= the: adjacent idler housing; a spindle shaft 'journalled: in each ofsaid spindle housings eccentrically of the adja-- cent idler shaft, ainut'coacting w-ithzeachof said idler: shafts and with the, adj acent spindle house ing for clamping saidthousings into,various positions=of adjustment-, andz-a, train of; gears ex,- tendingthrough each; set 0f; saidwhousings, for transmitting'motam memento-the: corresponding spindle-shafts 5. A multiple: drill assemblage, comprising, a casing;;a.-plurality of clamping-rings revolvably. adjustable-,upom said casing. and each .having an idler shaftefixedlyw attached theretoand projecting therefrom parallel,-to; the. ring axis, an idler housing; adjustable about, each: of -said 'ring. axes and; coac-ting; with; said-casing, a. spindle. nous-- ing; reuolvably;adjustableabouteach'of said idler. shaftsand coacting-a with; thee-adjacent. idler housing; a spindle; shaft. journalled v in, each. of said: spindle" housings-v eecentrically; of the adjacent. idler'shaft, means coactingdirectly with said:v idler shatter; for clamping. said.v housings against: said casing, in variouspositions of ad! J'ustmen-t; -anidler-gear; rotatable about each of saididl'er; shafts.- withinethe corresponding; set. of. said housings, ;c ommon -means-1,-for; rotating all of said. gears; andgears parrieda by said spindle shafts; and coacting, with; the. adjacent. idler gears.

6. Asmultiple-drill; assemblage; comprising; a casing; ,a plurality of clamping; rings revolvably adjustable upon saidcasing, and-,eachhaving an idler.- shaft fixedly attached thereto 1 and-proj ecting; therefrom-paralleL to sthe= ring axis, an: idler housing adjustable-1 about each ofisaid. ring: axes and coactingwith'. said casing, a spindle housing revolvably "adjustable. about .each: of said, idler shafts; and reacting- .with the .adjacent idler housing-a spindle shaft journalled in each-of saidspindle housings eccentrically of, the adjacent idler: shaft,;: clamping means coasting with each: of said-idler" shaftsgandwiththe. adjacent spindlehousing for-1.- clamping saidrings and housings into; various positionsot-adjustment, an idlen gear freely; rotatable about each of said idler: shafts; within :them Ir PQndinas t o Said housings-common; means-rfonrotatingallof.-.said

9 idler gears, and gears carried by said spindle shafts and coacting with the adjacent idler gears.

'7. A drill assemblage, -comprising,a casing, a clamping ring revolvably adjustable upon'said casing and having anidler shaftfixedly attached thereto and projecting therefrom parallel to the ring axis, an idler housing adjustable about said ring axisand coacting with said casing, a spindle housing revolvably adjustable about said idler shaft and coacting with .said idler housing,'a spindle shaft journalledin said spindle, housing eccentrically of said idler-shaft, means coacting directly with said idler shaft andthrough the housings with said ring for clamping said housings against said casing in various positions of adjustment, and means for rotating said spindle shaft. 7

8. A drill assemblage, comprising, a casing, a clamping ring revolvably adjustable upon said casing and having an eccentrically disposed idler shaft fixedly attached thereto and projecting therefrom parallel to the ring axis, an idler housing adjustable about said ring axis and coacting with said casing, a spindle housing revolvably adjustable about said idler shaft and coacting with said idler housing, a spindle shaft journalled in said spindle housing eccentrically of said idler shaft, means coacting directly with said idler shaft and through the housings with said ring for clamping said housings against said casing in various positions of adjustment, an idler gear rotatable about said idler shaft within said housings, means for rotating said gear, and means for drivingly connecting said gear to said spindle shaft.

9. A drill assemblage, comprising, a casing, a clamping ring revolvably adjustable upon said casing and having an idler shaft projecting therefrom parallel to the ring axis and revolvable to any position about said axis, an idler housing adjustable about said ring axis and coacting with said casing, a spindle housing revolvably adjustable about said idler shaft and coacting with said idler housing, a spindle shaft journalled in said spindle housing eccentrically of said idler shaft, clamping means coacting with said idler shaft and with said spindle housing for clamping said housings into various positions of adjustment, an idler gear freely rotatable about said idler shaft within said housings, means passing through said, ring for rotating said idler gear, and a driving connection between said idler gear and said spindle shaft.

10. A drill assemblage, comprising, a casing, a clamping ring revolvably adjustable upon said casing and having an eccentrically disposed idler shaft projecting parallel to the ring axis and revolvable to any position about said axis, an idler housing adjustable about said ring axis and coacting with said casing, a spindle housing revolvably adjustable about said idler shaft and coacting with said idler housing, a spindle shaft journalled in said spindle housing eccentrically of said idler shaft, the spacing between said spindle shaft and said idler shaft and between said idler shaft and the center of said ring being equal, means coacting with said idler shaft for clamping said housings and said ring against said casing in various positions of adjustment, and means for rotating said spindle shaft through said housings.

11. A drill assemblage, comprising a casin a annular series of clamping rings each independentlyrevolvable upon said casing and each having a rigid idler shaft projecting therefrom and away from said casing parallel to its carrier ring axis, an idler housing coacting with each of said idler shafts and being swingably adjustable therewith to any position about the adjacent ring axis, a drive shaft journalled in said casing centrally of each of said clamping rings, gearing connecting each of said drive shafts with the adjacent idler shaft, means coacting directly with each of said idler shafts for clamping the corresponding ring and idler housing to said casing, and a drill spindle shaft drivingly a sociated with the gearing coacting with each of said idler shafts. a

12. A drill assemblage, comprising-a casing, a clamping ring revolvable upon said casing and having a rigid idler shaft projecting therefrom and away from said casing parallel to the ring axis, an idler housing coacting with said idler shaft and being swingable therewith to any posiassociated with said gearing coacting with the idler shaft.

13. A multiple spindle drill head, comprising a body member having a plurality of cylindrical recesses therein; a plurality of cylindrical barrels rotatably mounted in said recesses; a spindle passing through the body member and the central axis of each barrel; a head On each end of the spindle engaging the body member and the barrel to retain same in coacting relationship; a plurality of drill holder carriers, each drill holder carrier being rotatably mounted on a barrel, and eccentric to the axis of rotation of the barrel; a plurality of drill holders, each drill holder being rotatably mounted on its drill holder carrier and eccentric to the axis of rotation of the drill holder carrier; a main drive shaft; and power transmission means between the drive shaft and the drill holders for rotating the latter.

14. A multiple spindle drill head, comprising a body member having a plurality of cylindrical recesses therein; a plurality of cylindrical barrels rotatably mounted in said recesses; a spindle passing through the body member and the central axis of each barrel; a head on each end of the spindle engaging the body member and the barrel to retain same in coacting relationship; a plurality of drill holder carriers, each drill holder carrier being rotatably mounted on a barrel and eccentric to the axis of rotation of the barrel, the inner surface of each drill holder carrier bearing on the outer surface ,of its barrel; means for clamping each drill holder carrier against its barre]; a plurality of drill holders, each drill holder being rotatably mounted on its drill holder'carrier and eccentric to the axis of rotation of the drill holder carrier; a main drive shaft; and power transmission means between the drive shaft and the drill holders for rotating the latter.

15. A multiple spindle drill head, comprising a body member having a plurality of cylindrical recesses therein; a plurality of cylindrical barrels rotatably mounted in said recesses, the under surfaces of the body member and the barrel being substantially co-planar; a spindle passing through the body member and the central axis of each barrel; a head on each end of the spindle engaging the body member and the barrel to retain same in co-acting relationship; a plurality of 

